Deglaciation of the eastern Cumbria glaciokarst, northwest England, as determined by cosmogenic nuclide (~(10)Be) surface exposure dating, and the pattern and significance of subsequent environmental changes

摘要

Four erratic boulders of Shap granite on the limestone terrain of eastern Cumbria have yielded cosmogenic nuclide (~(10)Be) surface exposure ages that indicate the area was deglaciated c.17 ka ago. This timing is in accord with other ages pertaining to the loss of glacial ice cover in the Yorkshire Dales and north Lancashire, to the south, and the Lake District, to the west, and constrains the resumption of landscape (re)colonization and surface and sub-surface karstic processes. Marked shifts in climate are known to have occurred since deglaciation and combined with human impacts on the landscape the glaciokarst has experienced a complex pattern of environmental changes. Understanding these changes and their effects is crucial if the 'post-glacial' evolution of the glaciokarst is to be deciphered.